Fix crucial comment

sudoku.py

@@ -190,7 +190,7 @@ for value in range(8,0, -1):
             all_paths = [new_path] + extended_paths
             paths[cell].extend(all_paths)
 
-# all_paths : list[Path] = [ path for cell in all_cells(solution) for path in paths[cell] ]
+all_paths : list[Path] = [ path for cell in all_cells(solution) for path in paths[cell] ]
 
 def get_cells(path: Path) -> Iterator[FilledCell]: 
     yield path[0].fr
@@ -212,6 +212,8 @@ def ilike(path: Path) -> bool:
     max_one_solved = len(given_cells) < 2
     return max_one_solved
 
+# print("all paths are", len(all_paths), "paths")
+
 hints : list[list[Thermo | Cell]] = empty_grid()
 used_cells: set[FilledCell] = set()
 num_paths = 4

sudokus/19.in

@@ -0,0 +1,9 @@
+006900030
+700008090
+300020704
+004006000
+089000650
+000300400
+405080002
+060500001
+010009300

sudokus/20.in

@@ -0,0 +1,9 @@
+850210000
+600007000
+219065400
+000042000
+100000002
+000630000
+004820163
+000400008
+000076094